Downdraft heating apparatus.



lBDB W. SAWYER. DOWNDRAFTv HEATING APPARATUS. APPLIOATION FILBDVPEB. 7, 1907. RBNEWED AUG. 12, 1909.

11 A ,TU Patented M3118, 1910.

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HOWARD DE WLFE SAWYER, F REVEEE, MASSACHUSETTS.

DOWNDRAFT HEATING APPTUS.

951,'tll3.

Application filed-February 7, 1907, serial No. 356,1!1513. Renewed August 1.2, 1909. Serial No. 512,59u.

To all whom 'it may concern.'V

lie it known that l, HOWARD DE Woman SAWYER, of Revere, in the county of Sudolk and State of Massachusetts, have invented certain new and useful Improvements in 'Downdraft Heating A paratus, of which the following isa speci cation.

The object of this invention is to provide improved hot-Water heating apparatus operating on the down draft principle and einbodying, ina suitable shell or casing, a succession of tubular' Water heating gratas, a tubular fuelsupporting grate and a similar super-heating grate or radiator above the iire,-these being connected in series at both ends of their enlarged headers, for'continw `ous upward circulation of the Water tobe heated and, by external delivery and return pipes', conducting the Water to radiators locatedin the rooms to be heated and rcturning it to the base lof the heater to repeat, in`

definitely, ,this circulation movement from bottom to`top. The casing is rectangular with a Skeleton frame of angle iron, to which the plates arev secured, and a lining layer of asbestos protects ,the casing and limits radiation therefrom. vThe fuel chamber and draft inlet being at top and the ashL pit and flue-opening at bottom, the 4normal caloric current is downward between the Water-containing tubular bars of the several gratw, the temperature increasin as the Water rises through the successive y hotter grate-tubes. The radiator at top of the. 9,5 repot or combustion` chamber receives the direct radiant hea-t of the fire. Dampered outlets from tho back lof the irepot into the funnel may serve to reverse the draft when desired.

In the drawing, Figure l is a vertical sec-- tion through the heater, Fig. 2 a like view taken on the 'line 2-2 of Fig. 1,' and Fig. 3

a horizontal section on line 3---3 of Fig. 1.l

Fig. 4 is an enlargedsectional detail of one The casing 10 Vis preferablyT formed of rectangular Wrought .iron or steel plates composing the four vertical Walls and the top and bottom of the heater. These plates will be secured by blts or rivets 11 to angle iron corner bars 12 irst united into a skeleton frame. The vertical plates are coated internally With a lining of asbestos, 13, to protect them from the intensity of the heat and limit its radiationv into the` room in which the heater is located. These lining Specication of Letters Patent.

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layers are preferably held, at intervals, to"L the respective plates. by thin metal Istrips or pieces 14, riveted to the plates, see Fi 1 and 2. These pieces may be extended 1nto definitely or any other holding means em-' ployed. The front Wall of the casing is furnished with three doors, the draft inlet and fuel door 15 at its upper portion, a rake-out door lsomewhat lower down, and an ash door 17 at the bottom. The rear Wall has an opening 18 near its lower end to connect with the funnel 1l) and give an outlet for the caloric current after the heat thereof has been largely absorbed or utilised in raising i the temperature of the Water. A direct out-4 let from the fire pot to the funnel may be' had by opening the damper Q0, shown closed in the short pipe-section 2l, Fig. 1. Such opening would close damper 20 at the base 75 of the funnel, both dampers being shown"as secured to the oscillating rod 23. The fueldoor will have an ordinary sliding or oscillating draft regulator to control the admission of air.

lnclosed Within the casing is the system of tubular grates and connections, comprising the fuel-supporting grate 25, a plurality of water heating grates 2G beneath it, and a super-heater or radiator 27 above it, these 85 grates being reversely inclined and succesv sively connected at both ends by risers 28,

Ato form a sinuous passage upwardly, about.'

as shown. Each grate has, as sho-Wn in Fig.

3, enlarged marginal tubes 29, with Which'ltl the slender tubular parallel bars connect laterally, their slightly tapering ends being simultaneously forced into the rows of perforations, shaped to receive them. Bypreference l use, for the fuel grate and the radi- 9h ator or super-heater, steel tubes three eighths inch in diameter with one fourth inch bore,

the grate tubes being spaced 1-5/16 inchesV between centers and the radiator tubes about one inch. For the-lower gratos the tubes 10o Will be of the same material, say onehalf inch diameter and more Widely spaced. 'lhe inclination Will be about 1-1/2 inches to the foot. These details 'of the gratos and connections vare here suggested as suitable and practical, but l do not design to Vlimit myself thereto. Through these small grate tubes the Water continually rises, the current divided into numerous fine streams, alternating With4 the larger marginal tubes and "11o risers, While the descending calorie current of great intensity, due to the direct action ot the tire and the burning of the generated top, and normal outletsI for the products ol gases in the combustion chamber above and below the fuel grate, passes downwardly hetween the tubular grate bars and impinges` with powerful heating effect on them and their connecting tubes. speedy heating et the Water, and its rapid movement upwardly serves to scour the tubes internally, While the inelosed streams prerent;- the possibility of melting or burning out the grate bars which would otherwise occur. The grates may he properly supported by lugs 30 beneath their Kmarginal tubes and secured to the easing. The water for circulation enters at the lower margin of the bottoni grate, as at'. 31, Fig. l, and emerges through pipes 5&2 at opposite ends l l l l l of the upper margin ot' the topmost. grate or superheatcr 2. liquely'd unite. extended to a succession ot radiatorsnot shown, located in several ditlerent rooms to be heated7 the hot water current passes, returning, more or less cooled, to the heated base through pipe 34, which, in Fig. :l is shown branched or direrging to enter both ends of the lfower grate. This circulation movement continues indefinitely.

I claim my invention 1. In a down-draft heating apparatus, an inelosing casing having a tuel chamber and door thereto at top, a succession ot' waterheating grates therein, andleonm-rted in series at each end and opposite sides, by en 'lhe pipes 252 extend oblai-ged risers, in combination with external circulation and return pipes, for beating rooms remote from the heater proper, s`u-b stantially as set lorth.

2. In a donf'itdrat't-heating apparatus, an inclosing casing having a skeleton frame of angle iron to Which the casing plates are se- ,ured, a fuel chamber and door thereto at rithence by pipe 253. duly eoinbustiox'i at the bottom, in cmnbination with tubular water-eontanung gratos and y connections therefor within said casing and with inlet and outlet pipes external thereto The result is the adapted to maintain a constant'A circulation of water exposed to the high heat within the easing, for the. purpose set forth.

il. In a down-draft heating' apparatus an inelosing easing having a fuel elmniber,door and air inlet thereto at top and an ash outlet. and funnel opening at bottom, in combination with a tubular tuel grate. a plurality of water heating grates ol' like charatler below. and a similar radiator or super heating grate above the l'uel grate, within thtI eas ing, and with tubular water connections' uniting said grates in series, for continuous water circulation upwardly through and roturning to the heater.y while the caloric current mores do\\'n\\'ardly between the grate bars7 sxibstantially as set Jforth.

el. ln a down dralt heatingapparatus an inclosing casing formed ot .metallic plates `united rornerwiae and provided with an asbestosI lining Isuitably secured thereto7 the t'uel door and drat't inlet being at top, the ash door and funnel opening` atl bottom and a ralt'e-out opening between them, in combination with a water'cont'aining fuel grate and a n'niltiplicity of water-heating tubes traversing the heating chamber below the grato and connected in series therewith and with conducting and return pipes to maintain a constant circulation, substantially as set forth.

In testimony whereof I have affixed my signature.v in presence of two witnesses.

Howlin) DE wenn: stuwen. l itnesses:

A. Il. Srnnonn, H. W. Lann. 

